TiO2 thin film crystallization temperature lowered by Cu-induced solid phase crystallization

We lowered the crystallization temperature of amorphous TiO2 thin films using a Cu catalyst as either a bottom or cap layer. The Cu bottom layer reduced the crystallization temperature of TiO2 by ~ 30 °C. Depth profile analyses by Rutherford backscattering spectrometry revealed that a very small amount of Cu was sufficient to induce full crystallization of the TiO2 film. Depositing the Cu cap layer and annealing at 210 °C for 3 h yielded a transparent anatase TiO2 thin film upon wet-etching the Cu cap.